1. Field of the Invention
The present invention relates to an image forming apparatus and a toner housing container.
2. Description of the Related Art
In electrostatic image forming apparatuses, an electrostatic latent image formed on a photosensitive body is developed with toner supplied from a developing unit and is transferred onto recording paper. After fixation, the recording paper is exhausted out of the apparatus. Since toner is consumed by such development, the consumed quantity is supplied by a toner supply unit. This toner supply unit is constituted as a portion of the image forming apparatus and has a toner housing container (toner bottle) detachably attached thereto. In an image forming apparatus such as this, if toner is consumed and the toner housing container empties, the empty container can be exchanged for a new one filled with toner.
The toner housing container is held by the toner supply unit. This toner supply unit is supported by the apparatus main body or the developing unit main body (a member which supports the toner supply unit will hereinafter be referred to as simply a main body). Under the state where the toner supply unit is held in a predetermined loading position on the main body by a stopper member, the toner supply unit supplies the toner of the toner housing container loaded in the toner supply unit to the main body.
As this toner housing container, containers having on the interior circumferential surface a spiral ridge extending from the bottom portion to the discharge opening are disclosed, for example, in Japan Laid-Open Patent Publication Nos. SHO 63-75769, HEI 7-140774, and HEI 8-95361, respectively. Each toner housing container is constructed so that it is approximately horizontally attached within the image forming apparatus and is rotated on its central axis to discharge the housed (stored) toner.
On the other hand, there is another toner supply unit as the related art of this invention which is not publicly known. This toner supply unit has a receiving bed for horizontally supporting a toner housing container. The toner housing container supported by the receiving bed is rotated by rotation means. This rotation conveys toner in the toner housing container to the discharge opening side and feeds the toner out of the toner housing container. This toner supply unit is rotated in a state in which the maximum outer-diameter portion (side surface portion) of the toner housing container is held in contact with the supporting surface of the receiving bed.
In the aforementioned cases, toner in the toner housing container is conveyed to the exit side by rotation of the toner housing container, but in the case where toner with poor fluidity is used, the quantity of toner on the interior surface of the toner housing container is increased, so there are cases where a large quantity of toner remains in the toner housing container, the conveying force is reduced, and a stable supply quantity is not obtained. Also, in the case where a toner housing container with a spiral groove formed in the interior surface is used, there are cases where this spiral groove is buried in toner, and likewise the conveying force is reduced, and a stable supply quantity is not obtained.
Japan Laid-Open Patent Publication No. HEI 8-95361 discloses a technique in which the exterior circumferential surface of a toner housing container is knocked to cause toner on an interior circumferential surface of the toner housing container to fall, thereby smoothly performing discharge of toner. In this technique, a protrusion is provided on the exterior circumferential surface, and a knocking portion urged in a direction in which the exterior circumferential surface of the toner housing container is knocked is provided in a means of holding the toner housing container. When the knocking portion rides across the protrusion, the toner housing container is knocked.
However, in this conventional technique, if the toner housing container is knocked in the state in which toner is placed on a push-out portion, toner raised up on the push-out portion will fall into the toner housing container due to vibration and therefore disadvantageously the discharge of toner will be disturbed.